Director of the Bureau of Standards

to the

Secretary of Commerce and Labor

for the

Fiscal Year Ended June 30, 1909

Washington

Government Printing Office

1910

Annual Report

of the

Director of the Bureau of Standards

to the

Secretary of Commerce and Labor

for the

Fiscal Year Ended June 30, 1909

Washington

Government Printing Office

1910

REPORT

OF THE

DIRECTOR OF THE BUREAU OF STANDARDS.

Department of Commerce and Labor,

Bureau of Standards,

Washington, July 1, 1909.

Sir: I have the honor to submit the following report of the work

of the Bureau of Standards for the fiscal year ended June 30, 1909:

DIVISION I—ELECTRICITY.

Electrical measuring instruments, of which a great variety of types

and sizes are employed in the measurement of electrical current, voltage, and power, are tested by comparing them with certain standard

instruments which have been carefully investigated and which are

referred back from time to time to the fundamental electrical standards which it is one of the functions of the Bureau to establish and

maintain. These fundamental electrical standards represent the

unit of resistance and the unit of electromotive force or voltage, the

values of which,- and their method of preparation, are fixed by law.

They are not, however, chosen arbitrarily, but are so specified as to

be simply related to the absolute units of resistance and voltage,

which latter are logically derived from the fundamental units of

length, mass, and time—that is, the centimeter, the gram, and the

second.

The experimental realization of suitable concrete electrical standards involves two distinctly different steps or stages—first, the determination of their values by means of what are called "absolute electrical measurements," in which is demanded the complete theory of

the methods and instruments employed, the most perfect instrumental equipment, and experimental skill of a high order; second, the

development of concrete material standards by means of which the

values found in these elaborate absolute measurements may be permanently preserved.

This work was first done (chiefly by European investigators) a generation ago, and our present legal values were fixed on the recom-
4 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

mendation of the International Electrical Congress of 1893. But

subsequent work has shown that the values then adopted were not

as accurate as they were supposed to be, and whereas England,

France, America, and some other countries have continued to employ the values then chosen, Germany, Austria, and other countries

have used slightly different units for the measurement of current

and voltage.

The International Electrical Conference which met in London in

October, 1908, adopted a new value for the unit of electromotive

force, but left to a newly constituted international committee the

completion of the specifications of the concrete standards, inasmuch

as agreement could not be reached at the conference. This committee of twenty members represents eleven different countries, three

of the four American members, including the secretary and treasurer

of the committee, being from the Bureau of Standards.

In order to settle some of the disputed questions involved, and to

clear up some of the obscure points at issue, the international committee has arranged to have an international cooperative investigation undertaken by representatives of some of the largest national

standardizing institutions, including this Bureau; and at our invitation the work is to be carried out during the coming fiscal year at the

Bureau of Standards. This work is of prime interest and importance,

and will probably go far toward securing not only greater precision,

but, what is even more important, international uniformity among

the civilized nations of the world in electrical units and standards.

In view of the international conference of last October and the

approaching international cooperative investigation, considerable

work has been done during the year on the subject of electrical standards and absolute electrical measurements.

RESISTANCE AND ELECTROMOTIVE FORCE.

Although the London International Electrical Congress selected

the ohm and the ampere as the fundamental electrical units in terms

of which all electrical measurements are to be expressed, the Bureau

has found it impracticable to adopt the recommendations, owing to

variations still found in coulometer measurements, which are at present under investigation. The results of electrical measurements will

therefore be referred to the basis of reference heretofore employed,

namely, the ohm and the Weston standard cell. During the past year considerable progress has been made in the

construction of primary mercurial resistance standards. The calibration of a number of carefully selected capillary tubes has been

completed, and considerable preliminary work has been done in other

directions.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 5

Further work has been clone in cooperation with the Chemical Division in the investigation of equilibrium conditions in the Weston

normal cell, which have been called into question, and some promising

results have already been obtained. The comparison of standard

cells, set up during the past year, at the English National Physical

Laboratory and by other investigators has verified the accuracy of

reproduction claimed in former reports—several parts in 100,000.

An investigation of the conductivity and temperature coefficient

of copper and aluminum had been undertaken at the request of the

committee on standards of the American Institution of Electrical

Engineers and of a number of copper refiners and wire manufacturers who have generously offered to cooperate with the Bureau in furnishing and drawing samples. This work will include an investigation of commercial and specially prepared materials, the influence

of traces of added impurities which so largely affect the conductivity,

and the influence of drawing and annealing.

An experimental and theoretical study has also been made of the

vibration galvanometer used in precision measurements with alternating currents and has resulted in improvements which further

increase its already high sensibility.

The above investigations will be continued as far as permitted by

the routine testing of apparatus submitted for certification, the volume of which has shown a steady increase since the organization of

the Bureau.

INDUCTANCE AND CAPACITY AND ABSOLUTE MEASUREMENTS.

The work on the absolute measurement of electric current has

been continued during the year and a new value obtained for the

electromotive force of the Weston normal cell. An investigation of

the silver coulometer is being carried out, which promises to yield

results of much scientific value. A new method for the absolute

measurement of resistance has been devised, and the necessary apparatus constructed; work of carrying out the measurements will be

done during the next fiscal year. Investigations of inductances and

condensers have been continued. Tests have also been made of

standards of inductance and capacity and of electrical instruments.

The work in this section touches the practical application of electricity less directly than in other sections of the Electrical Division,

being largely concerned with the fundamental measurements which

underlie practical applications.

MAGNETIC MEASUREMENTS.

The principal demands for magnetic testing comprise tests to determine the magnetic permeability of specimens and to determine

the energy losses occurring in the magnetic material used in the con-
6 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

struction of electrical apparatus, such as dynamos, motors, and transformers. Improved methods for conducting both of these tests have

been in the course of development for some time, and have now

reached a satisfactory stage. Circular No. 17 has been issued, an- nouncing the readiness of the Bureau to conduct magnetic tests for

the public and prescribing the conditions under which tests are made.

The Bureau has prepared a number of bars of different grades of

steel, and different sizes, whose magnetic properties have been carefully determined. These are supplied to the public, when desired, for

the purpose of checking magnetic measurements made with commercial or other apparatus.

Preparations have been made for testing the spirals of bismuth

wire which are used for the measurements of intense magnetic fields,

and several of these spirals have been tested. . Special investigations

were completed during the year to determine the effects of high temperatures and of low temperatures upon the magnetic properties of

manganese-steel, the alloy used being one which is very nearly nonmagnetic; to determine the errors incident to testing material in the

form of rings; to discover whether the energy losses due to alternating

magnetization are dependent upon the wave form of the electrical

current used for magnetizing, and to determine the relative merits of

silicon-steel and ordinary steel for use in electrical transformers.

ELECTRICAL MEASURING INSTRUMENTS.

The demands made by the public upon the Bureau for the testing

of this class of apparatus have increased considerably during the

past year. In addition to standard instruments regularly tested in

the past, the work of testing current and potential transformers has

been considerably extended; precision methods of determining the

constants of these transformers have been developed, and more of

these transformers have been tested during the past year than in all the preceding years of the work of the Bureau. With the increasing

development of high voltage power plants, especially in the West,

these transformers have come into a place of great importance, as

large amounts of power bought and sold are measured by their aid.

In addition to the usual work for other government departments,

special work includes tests made for the National Museum, the Isthmian Canal Commission, the Commissioners of the District, and the

general supply committee. Assistance has been rendered to the latter

committee in the work of testing and inspecting manufacturers'

samples of electrical goods and supplies.

Progress has been made on the design of labor-saving electrical

testing instruments, which are soon to be built for the use of the

Bureau.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 1

PHOTOMETRY.

Reference was made a year ago to the effort which the Bureau was

making to secure uniformity in the value of the standard candle in

England, France, and America, and to secure the general adoption

of this international candle by the gas and electrical industries in

this country. The proposal made by this Bureau was accepted

by the national laboratories of England and France, and accordingly, on July 1, our unit of light was decreased by 1.6 per

cent. This new value of the standard candle will hereafter be the

standard for all photometric measurements in this country, both for

gas and electric practice. It has been indorsed by engineering societies, and will gradually be recognized by the laws of the several

States. Heretofore the "candle" has been spoken of in state laws

and regulations as the standard of light, but different sperm candles

differ so much that the unit so determined has been quite variable.

Hereafter the "candle" as a unit should be understood to mean not

the light of a sperm candle, but the value of the unit of light maintained by this Bureau.

A special investigation will be made during the next fiscal year of

flame standards employed in photometry, for the purpose of determining their degree of reliability and, if possible, to improve one or more of them for the practical uses of gas photometry.

The Bureau has inspected and tested samples of electric incandescent lamps purchased by several of the government departments,

amounting altogether during the past year to about 500,000 lamps.

These tests are important, as they insure the delivery of good lamps.

Without tests inferior lamps would certainly be furnished in many

cases. The standard specifications for carbon-filament incandescent

lamps issued by the Bureau two years ago were revised during the

year, and new specifications added for the new metal-filament lamps.

These specifications have been prepared in conjunction with engi- neers representing the manufacturers and some of the government

departments, and have been adopted as standard by the manufacturers and by the Government, and are used by many purchasers of

lamps.

A considerable amount of work has been done during the year on

color photometry, including the determination of the color values of

various artificial illuminants in terms of average daylight, and the

method of combining artificial illuminants to produce a color equivalent to that of daylight illumination.

Tests of gas and electric lamps to be used as standards by the gas

and electric companies and by manufacturers have been made during

the year in considerable numbers. No provision has yet been made

for arc-lamp testing, owing to lack of space and insufficient personnel.
8 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

DIVISION II.—WEIGHTS AND MEASURES.

The routine testing in the Division of Weights and Measures increased nearly 200 per cent over the previous year and the force,

equipment, and space at its disposal were taxed to the utmost to

meet the demands made upon the division.

LENGTH MEASUREMENTS.

About twice the number of length measures were tested (approximately 570), including steel tapes, level rods, gages, and standard

bars, over 80 per cent being either for the federal or for the state

governments. The increase was due to the extraordinary demand

of the Philippine government, which inaugurated a new weights and

measures law on January 1, 1907. Other increases were due to the

replacement of apparatus destroyed by fire in the building occupied

by the Geological Survey, and to the further fact that practicaUy all purchases now made by the Government are on specifications or according to samples submitted to the general supply committee.

Urgent requests have been made for the determination of the

expansion of various alloys and materials, and to determine the dimensions of gages with a degree of accuracy recently made possible by

the extraordinarily accurate gages now being manufactured by a Swedish firm. This work was necessarily deferred, but the development of apparatus for the testing of screw threads and the determination of expansions will be taken up energetically next year when

new assistants are available.

The construction of the new meter comparator for length standards has reached a point where comparisons of standards in the old

troughs or boxes is possible. The new iron carriage, the invar beam,

and the microscope have been placed in position, and comparisons

already made indicate a marked improvement in the results over

those obtained with the old comparator. The box for comparing

bars in ice and the arrangement for temperature control, including

heating coils and water circulation of the double box, are not completed, but it is expected that they will be finished in the coming year.

During the year the Bureau received the platinum-iridium meter

bar purchased from the French Government and graduated by the

Societe Genevoise. This bar was one of those made of the alloy of

1874, prepared by the French section of the international committee,

because it contained a slightly larger percentage of certain metals

than had been specified. It is of the same cross section as the prototype meters, and, with the graduation by the Societe Genevoise

and the comparison with the standards at the International Bureau,

is in every other respect as satisfactory a standard as the prototype
REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

meters. After being graduated it was compared and calibrated at

the International Bureau of Weights and Measures, in Paris, and its

coefficient of expansion determined.

Arrangements were completed during the year for comparing metal

tapes with the bench standard, the tapes being supported at any desired points, and notice of this fact was given in a new edition of

Bureau Circular No. 2. Urgent demands were also made upon the Bureau for the standardization of master screws and preliminary designs of apparatus for

such work were begun. The extreme difficulty of measuring the

various dimensions of any screw with sufficient accuracy to state in

advance that it will fit a certain nut is evident to anyone who has

had experience in such work, and up to the present time no apparatus

which more than approximately fulfills the desired conditions has

been constructed. Nevertheless, the Bureau should be prepared to

settle any dispute that may arise between manufacturers of screws and pipe threads as to compliance with the standard specifications

for such threads, and every effort will be made to develop apparatus

to satisfy the exacting needs of such work.

MEASUREMENTS OF MASS.

As in other sections of the division, the routine testing of standards

of mass showed a substantial increase of something over 50 per cent.

This work, with the necessary cross-checking and intercomparison

required to maintain satisfactory values for the secondary standards,

left little or no time for the investigations which had been planned

by this section. A large part of the routine work, as heretofore, was

for the weights and measures inspection service of the several States.

It is gratifying to note a great improvement in the character of the

weights now submitted for test over those submitted a few years ago.

Solid one-piece weights .protected by a coating of gold plating and

made in accordance with the specifications of the Bureau may now

be obtained from several manufacturers.

In response to the demand of manufacturers and state and local

sealers tolerances for commercial weights, based upon those in use

abroad, have been prepared, and will be announced in a circular

some time during the next year.

The alterations, now practically completed, in the 25-kilogram

precision balance will greatly add to the facility with which it can be

used. What is most urgently needed in the form of equipment at

the present time is a precision balance for loads of 200 grams and a

quick-acting balance for loads of 30 grams. The maker of the small

assay balance which has proved so satisfactory has been induced to

design and construct a special balance of the desired capacity which

it is hoped will be completed during the coming year.

2S243—10 2
10 REPORT OF DIRECTOR OP BUREAU OF STANDARDS.

A duplicate of a large part of the present equipment, as well as additional working space and assistance, must soon be had unless the division can be relieved of some of the demands upon it.

VOLUMETRIC MEASUREMENTS.

During the year approximately 9,500 pieces of glass volumetric

apparatus were tested, as compared with about 3,000 in the previous

year. About 6,000 pieces additional were examined and rejected

without actual test on account of defects of construction, design, etc. This apparatus consisted of flasks, transfer pipettes, measuring

pipettes, burettes, and graduates, the larger portion being for government laboratories, and are of great importance, as in tins way

precision is provided for the general scientific and technical work of

the Government.

In addition to the glass volumetric apparatus, 162 metal and paper

capacity measures were tested. These included standards for several

States and municipalities.

HYDROMETRY.

Satisfactory progress was made during the year in placing the

hydrometer work of the Bureau on an excellent basis.

Specifications for the construction and manipulation of hydrometers, as well as density tables for use in hydrometry, were prepared

during the year and published in the form of circulars (Nos. 16 and

19). The primary standards of the Bureau were carefully calibrated and methods of testing developed. Over 1,000 hydrometers,

including manufacturers' standards, alcoholometers used by the

United States Internal-Revenue Service in the collection of duty on

spirits, and hydrometers for various industrial uses, were tested.

TIME MEASUREMENTS.

As a preliminary to the testing of watches for the public several

sets of watches loaned by different manufacturers were tested as to

their rates under varying conditions, in order to determine the toler- ance to be allowed by the Bureau in issuing certificates. The test of

the first lot was completed in July, 1908. A second lot of 50 watches,

loaned directly by the manufacturers from stock, were next tested.

This test was begun in November, 1908, and finished in April, 1909.

A test of a third lot of 54, also loaned by the manufacturers but supposed to represent the better regulated watches of the regular product of high-grade watches, was begun in April, 1909, and is still in

progress.

All of the above watches were tested for variations of rate with the

five changes of position for which high-grade watches are usually
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 11

adjusted, viz, dial up, dial down, pendant up, pendant right, and

pendant left. The effects of changes of temperature also were observed between 35° and 100° F. The variation of the rate throughout the day was ascertained by readings taken at different hours.

It is expected that the computations and regulations based upon

them and to be followed in the testing of watches will be completed

within the ensuing year. Before beginning the regular testing of

watches, however, it will be necessary to construct a hot-and-cold

room for temperature tests and to modify and extend the equipment.

The time on which the watch readings are based was obtained from

a Riefler clock mounted in a constant temperature room in the basement of the physical laboratory. For one period of a month the cor- rection of the clock gradually changed through less than 0.4 of a second without adjustment of the regulation being made during that

period. The correction of the. clock is obtained by comparison with

the noon signal of the Naval Observatory received at the Bureau by

wireless telegraph from the Washington Navy-Yard station. This

service has been interrupted frequently for considerable periods during the year, due to changes being made in the sending station at the

navy-yard, at which times it was necessary to obtain the signal by

telephone.

INSPECTION OF TRADE WEIGHTS AND MEASURES.

The fourth conference on weights and measures was held on December 17 and 18, 1908, and was well attended by delegates from

different parts of the country. The reports of the delegates indicated that satisfactory progress is being made to improve the methods of inspection in New York, Massachusetts, Ohio, and Kansas,

new and better laws having been enacted, while in Pennsylvania,

Colorado, and New Jersey bills were considered by the legislatures.

A recommendation was adopted urging an amendment to the purefood law to require the weight, value, or number of the contents to

be plainly marked on all commodities put up in sealed packages.

This is of importance to the consumer in order that he may know

exactly what he is purchasing. At present where sizes are not fixed

by law there is nothing to prevent anyone from decreasing the size

of the package put up without the purchaser being aware of the

change. Evidence on all sides shows a widespread interest in the

subject by individuals and various national organizations.

The appropriation of $10,000 made by Congress for an official investigation as to the extent that fraudulent weights and measures

are used in different parts of the country is now available, and plans

are completed for securing two experienced inspectors by civilservice examination to make a personal inspection in a number of

cities and towns in various States. They will, however, practically
12 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

cooperate with the local official, if there be any, and endeavor to get

information that will be first hand and reliable.

The general demand for better inspection of trade weights and

measures, as well as the unification of the state laws on the subject,

has caused a number of the States to call on the Bureau for the verification of both old and new standards. New Mexico, Kansas, and

New York have purchased new equipment for their state sealers,

while Massachusetts submitted for verification the standards furnished many years ago by the Federal Government.

DIVISION III.—THERMOMETRY, PYROMETRY, AND HEAT

MEASUREMENTS.

The tests completed during the year were as follows: 12,718 thermometers, including 504 high-temperature thermometers, 1,287

laboratory and special thermometers, and 10,927 clinical thermometers; 5 optical pyrometers, 22 thermocouples, 8 pyrometer galvanometers, 5 resistance thermometers, 159 flash-point and viscosity

tests of oils, 41 standardized heat samples, and 6 other tests involving

heat measurements; in all about 12,964 separate tests, an increase

of nearly 40 per cent over the preceding year. The increase in the

testing of the higher grades of thermometers was about 125 per cent,

necessitating a very considerable increase in the amount of time

devoted to this testing and emphasizing anew the need for a better

establishment of the scale of temperature up to 500 ° C.

At the urgent request of chemists, engineers, and manufacturers

this division, in cooperation with the Optical Division, is now furnishing standardized heat samples of known heat value for the

standardization of combustion calorimeters. The practice of awarding large contracts for fuel on the results of determinations by combustion calorimeters is growing rapidly. The preparation of these

heat samples, and the standardization -of the finely graduated thermometers used in the tests, have already done much to increase their

accuracy and to bring them to a uniform basis. Thus far the work

is limited to furnishing analyzed samples of cane sugar of the highest

purity. The determination of the heats of combustion of other substances, however, such as benzoic acid, naphthalene, and anthracene, is also under way.

By thus enabling chemists and engineers to test the accuracy of

their apparatus and methods the Bureau is relieved of such routine

testing as can be done as well in private laboratories, while accomplishing the important end in view, viz, the use of standardized apparatus and methods to enable different observers to obtain strictly

comparable results. Accordingly, the determinations of the calorific

values of fuels in this division have been limited to cases where the

results of other observers disagree or where tests were made for

another department of the Government.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 13

In view of the urgent need for data for engineers, corporations, and

public-service commissions, work has been done upon new apparatus

for determining the heats of combustion of gases and intercomparison

of the various types of calorimeters that are beginning to be widely

used in the gas industry. This work will be carried forward rapidly

during the coming year.

Upon request of the refrigeration industry the experimental work

in determining the specific heats of calcium-chloride brines was completed during the year. This work is of importance to more efficient

refrigeration engineering. Brines of very different chemical composition were included in this work, and two entirely different methods

of calorimetry were used, the results by the two methods showing

excellent agreement.

The use of cooling curves in metallurgical research is such that a

description of methods used to obtain cooling curves of metals and

other materials, with a brief analysis of their characteristics, has

been published and will aid the application of such graphic methods

to temperature work.

Pyrometers of almost every type used for the measurement of

high temperatures are now being submitted for test. This is encouraging evidence of the increased application of scientific methods in

those industries whose products depend upon the measurement or

control of high temperatures. Until recently the eye of the workman,

so subject to variable influences, was the only method in use in this

country for estimating high temperatures; to-day pyrometers are found in use in rolling mills, in the ceramic and glass industries, in the

manufacture of carbons, etc., and in various chemical operations.

As nearly all the leading types of pyrometer are used in the laboratories of the Bureau, this division has been able to furnish information

to representatives of-many industrial plants about to introduce pyrometric methods in their works. This is an important feature of the

work of this division.

An investigation was completed in this division, several years ago,

upon the order of accuracy attainable with optical pyrometers in

which the temperature of an incandescent body is estimated by the

amount of light or heat emitted by it. Instruments of this type

could, under proper conditions, be used to measure the highest attainable temperatures, and the several types of pyrometer examined

showed excellent agreement even at the extreme temperature of the

electric arc. Optical pyrometers were then just being introduced

into use. They are now widely used in the industries, largely as a

result of the Bureau's work. Since the light and heat radiated

varies vastly with different materials, it becomes necessary to investigate the radiation from such substances as iron, copper, carbon,

glass, fire clay, etc., to which these pyrometers are being applied in
14 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

the works. A research upon copper disclosed the fact that the radiation from the colder oxidized solid metal may exceed that from the

clean surface of the molten metal, and that in some.cases the indications of optical pyrometers may be in error by hundreds of degrees.

The results are being published in the Bulletin.

The growing use of methods of temperature measurement based

upon the change in electrical resistance of a platinum wire, and the

high order of accuracy attainable by this method, led to an extended

investigation of platinum resistance thermometry at high temperatures. The aim was to ascertain the advantages and limitations of

such thermometers at high temperatures, the order of accuracy

attainable, the effect of impurities in the wire, and the changes produced by exposure to high temperatures. These thermometers were

also used to determine the melting and freezing points of certain

metals, to determine the accuracy with which metals from the leading

firms could be used to give "fixed points" for the high-temperature

scale and for the calibration of pyrometers. This investigation was

completed during the year and the results will soon be published.

In order to improve the data needed for expressing temperatures on

the absolute thermodynamic scale, the ultimate goal of all temperature measurements, the work of Joule and Thomson on the expansion of gases will be repeated and extended. This work has also a bearing on methods of liquefying gases, and hence on refrigeration,

and on processes for the commercial separation of the oxygen and

nitrogen of the air.

The theory of the Hampson gas liquefier was studied to obtain more

precise insight into the working of this commonly used machine and

the best conditions of economic operation. The results are now being

published. Improvements in liquefying processes suggested by this

investigation will be embodied in the apparatus now being designed.

The greatly increased demands for testing made on this division

during the year have retarded some important investigations of fundamental importance to the usefulness of the division, such as the

intercomparison of the several datiation laws, as a basis for the hightemperature scale; the establishment of the standard scale of temperature in the interval 100° to 500° C, and the construction and use

of a standard gas thermometer for the determination of important

fixed points of the temperature scale.

The number of clinical thermometers submitted for test during the

year is 30 per cent greater than in the preceding year. The Bureau

has continued the practice of loaning standard thermometers to the

manufacturers of clinical thermometers, with most satisfactory results,

the accuracy of practically all the product of American manufacturers,

exceeding some 500,000 t hermometers per annum, being thus controlled

by standards loaned by this Bureau.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 15

DIVISION IV.—OPTICS.

During the year some important researches have been made in the

Optical Division, which includes radioruetry, spectrometry, polarimetry, and interferometr3r . Such researches are valuable in determining physical constants and the properties of materials, supplementing other methods used for this purpose. Besides the researches

mentioned, many optical tests have been made for the Government

and the general public, such as telescopic and photographic lenses,

prisms, samples of glass, polariscopic apparatus, and sugar analyses.

SPECTROSCOPY.

The investigations made by this section during the past year relate

chiefly to improvements in the methods of testing optical instruments

and materials, and to the methods of constructing reproducible primary

standards of luminous intensity, of pure color, and of spectral intensity. A resolving power test for objectives and optical instruments

was developed and described in the Bulletin. A new method of computing lens corrections has been devised and applied, and methods for

the complete testing of high-grade photographic objectives have also

been developed and outlined.

The study of the luminous equivalent of radiation was completed

and published during the year. This problem underlies the theory of

light measurement and the establishment of a rational absolute scale

of luminous intensity. A method has also been developed for constructing a rational color scale and establishing primary standards of

pure color. This is an important subject, and one which has many

industrial and technical applications. Conducting helium has been

further studied as a standard of total intensity and spectral intensity.

A source giving discrete spectral lines of fixed known relative intensity

is of great importance in the testing of photographic plates and other

work.

A precision optical bench, specially designed for determining the

oblique aberrations of high-grade lenses, has been installed and is in

frequent use. Samples of optical glass were received for test, some

of which were for use in large astronomical telescopes. Fifteen photographic plates were examined as to size and uniformity of grain and

resolution of image. A series of secondary color standards was

examined and compared with the primary standard colors. Many

spectroscopic tests have been made for different chemists, and numerous intending purchasers have sought the advice of the Bureau before

buying various optical instruments.
16 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

RADIOMETRY.

The radiometric work of the Bureau includes the investigation of

the laws of radiation of various substances, and also the instruments

and methods used in such investigations. During the past year considerable time was devoted to the improvement and testing of radiation meters. This is of the greatest importance in the investigation

of the radiation laws of a uniformly heated cavity, or so-called black

bod}', in which the emissivity is independent of the composition

of the inclosure. The accurate determination of the radiation constants of the black body is therefore of the highest importance, for

it is the only standard of reference in numerous fields of research.

One promising application of these radiation constants is in the ex- tension of the scale of temperature beyond the present limits. With

this end in view, a series of preliminar}7- spectro-radiometric measurements have been made, the results of which would have been

considered nighty satisfactory when compared with previous work.

However, since the object in view is the highest attainable accuracy

with instruments and methods now available, this investigation is

being taken up anew with an improved vacuum bolometer and with

various other instrumental improvements.

In addition to this problem, further observations were made on the

selective emission of solids, and on the lack of sensibility of the eye

to red light when apparently watching two incandescent lamps in

color. Additional data on "water of crystallization" was also obtained. This is an important problem in mineralog}*, and, since the

spectro-radiometric examination of minerals seems to be able to give us information not obtainable by chemical and other physical tests,

further work has been undertaken on this subject.

POLARIMETRY.

The work of this section has been marked during the year by an

increased interest both by scientists and manufacturers, due to the

fact that the Bureau is able to make immediate practical application

of its research work in this growing field, thereby directing public

attention to the results attained. The importance of applying the

most accurate scientific methods of polarimetry to the collection of

the revenue on sugar and to industrial processes is increasing. For

this purpose, among other tilings, large quantities of pure sugar are indispensable. The problem of producing relatively large quantities

of this material, of unexcelled purity, has been successfully solved by

recn-stallization in a vacuum. The demand on the Bureau for samples of this sugar is rapidly growing and many samples were sent out

during the year for scientific use. The distribution of such samples
REPORT OP DIRECTOR OF BUREAU OF STANDARDS. 17

for standardization purposes marks an important step in optical

measurements and calorimetry.

A further study of the quartz compensating polariscope has been

completed and the results published in the Bulletin. In consequence

of this work it now seems practicable to produce an instrument of

the compensating type with an adjustable polarization angle as large as 15°, thereby giving sufficient light to permit of the direct polarization of the darkest sugars and molasses, and eliminating the litigation which results from the inaccurate methods now in use. Much time has been spent in further study of methods of producing

monochromatic light of great intensity. Suitable monochromatic

sources, uniformly distributed throughout the visible spectrum, are indispensable for polarimetric measurements. A combination of sources and methods of purification has now been obtained, making

it unnecessary to depend on the uncertain sunlight of this locality.

The cooperation with the customs service in increasing the accu- racy of the tests on dutiable sugars has been continued with gratifying results. The regulations for this work prepared by the experts

from the Bureau cover the methods, instruments, and procedure,

and rigidly define the scientific basis upon which the revenue is collected. A new polarizing tube suitable for the customs service and

commercial testing has been designed. One thousand three hundred

and six analyses were made during the year.

DIVISION V.—CHEMISTRY.

The Chemical Division has continued, with a somewhat limited

force, to assist the different bureaus of the Government in checking

their supplies and reaching conclusions, in some instances, on which

to base future specifications. This work has grown since the establishment, during the year, of the general supply committee for the

government departments. Much of the labor of testing supplies

offered by bidders under the new system of purchase has devolved

upon this Bureau, and the Chemical Division has had its full share.

The routine testing of this division has more or less directly con- cerned every department and bureau of the service. Equally important with the testing is the study of the practical and scientific basis

for specifications, the desirable qualities in materials, their accurate

description in terms of physical and chemical properties which may

be measured or tested by standard tests and analyses, standard

methods of sampling, standard instruments and methods of testing,

and finally the preparation of standard specifications for the guidance

of the manufacturer and purchaser. This work should eventually

lead to the adoption of such specifications for all materials purchased,

and definite tests, so as to avoid the personal element in disargee-
18 REPORT OF DIRECTOR OF BUREAU OF STANDARDS.

merits. With the increased working force authorized by Congress

for the coming year it is hoped to be able to meet most of the demands

arising from this source. Among the important studies that the Bureau has undertaken for

the Government may be mentioned an extended experimental re- search upon certain properties of celluloid and other pyroxalin plastics

for the Steamboat-Inspection Service. Besides several other investigations of less magnitude there were completed during the year

about 2,116 tests and analyses, which may be classified broadly as follows: (1) Writing and printing inks, paper, and mucilage, 1,732,

of which the larger part were of papers for the Government Printing

Office; (2) lubricating and other oils, turpentine, paints, and related

materials, 306; (3) miscellaneous materials, such as rubber, boiler

compounds, brines, flooring compositions, boiler tubes, stereotype

metal and other alloys, steels, glass, silks, and a variety of other

materials, 78.

The distribution of analyzed and certified standard samples of

steels and irons of definite composition has met with great success,

the demand increasing 30 per cent over the previous year. This work,

undertaken at the request of the American Foundrymen's Association, enables the metallurgical industry to keep constant and reliable

check on their analyses, upon which depend so largely the success of

the industry. The number of standard iron and steel samples furnished was 687, against 465 the year before. Provision has been

made for adding largely to the variety of these analyzed samples in

order to meet the growing calls from various directions. Cooperative

relations have been entered into with the American Brass Founders'

Association, at its request, with the view of furnishing analyzed samples of brasses and other alloys and the improvement of methods of

brass analysis in that industry.

The Chemical Division will also cooperate with other divisions of

the Bureau in certain very important problems, such as (1) the preparation and testing of pure materials used in the construction of standards of electromotive force; (2) the preparation of several substances

of the very highest degree of purity and the determination of the

physical constants of these substances for use as standards in calorimetric work; (3) the study of flame standards for use in photometric

work; (4) the determination of the physical properties of the metals

and alloys used in the arts.

ENGINEERING INSTRUMENTS AND MATERIALS.

The standardization of engineering instruments and testing of materials showed a marked increase over the previous year. The demand

for the calibration of engineering instruments and the determination
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 19

of the physical properties of materials has taken practically the entire

time of the available assistants, thus restricting the attention given

to investigations and the development of methods.

Much time and labor have been devoted to the collation of reliable

information and data for the government departments and the public. The diffusion of such knowledge is of decided aid to industrial

and engineering progress. In many cases, however, sufficient dependable information is not available, and the Bureau has been urged to

take up investigations which would furnish it, including such subjects as methods of measuring gases at high velocities; properties of

metals and alloys; standard specifications for leather belting; relative merits of oak and hemlock tanned leather; rubber hose; bookbinding cloths; relative life of iron and steel pipe; prevention and

removal of effloresence on brick walls; standard textiles; wool conditioning and sampling; efficiency of water meters, and discharge

capacity of different sizes of pipe; relative merits of paper-testing

apparatus; standard methods of .testing paper and paper fibers, and

dynamic tests of metals.

Many special researches have been delayed during the year by

extensive demands along other lines. However, an investigation

of the present methods of calibrating anemometers is progressing,

and recent advances in aerial navigation accentuate the need for

this work, especially for higher velocities. Further work upon bookbinding cloths has been completed and is available for publication.

The results of this research have been practically applied in the

binding of government publications, and book cloths are now being

manufactured upon the standard specifications thus prepared. Many

public libraries are buying their cloths for bookbinding upon these

standard specifications and the demand for the reports of this investigation shows how quickly the value of such researches is appreciated

and utilized. A study of methods of determining the absorption

and adhesion of mortar to specimens of different absorption capacities is underway, the results of which are not yet ready for publication. Four American paper testers, for determining bursting

strength, are being studied to determine the effects of humidity, rate

of operation, intensity of clamping, and effect of imperfections. The

verification of the phloroglucine method for determining the percentage of ground wood in papers is complete and ready for publication. While more exact than microscopic analysis by fiber staining,

the phloroglucine is best applicable to grades of paper for which the

microscopic method is fairly adequate. It was possible to begin the

investigation of lubricants. The action of a standard oil tester is being studied to determine the conditions which influence its readings, the possibility of securing concordant results, and to investigate
20 KEPORT OF DIRECTOR OF BUREAU OF STANDARDS.

the relation between viscosity, flash point, and coefficient of friction.

This work is essential to the formulation of standard tests and specification for oils, a matter which deserves early attention.

The tests of engineering instruments and materials increased more

than 100 per cent over the previous year, and included 52 tests of

instruments, such as anemometers, manometers, paper testers, pres- sure gages, gas cylinders, and other apparatus; 84 samples of metals,

such as steel and iron, electric welds (steel), manganese bronze, wire

(special alloy), lead pipe, and flexible copper hose; 100 samples of

building materials, such as cement, concrete, brick, composition

flooring, rock, terra cotta, and wood; 3,191 samples of papers, textiles, and cordage; 96 samples of rubber and leather goods; 66 lubricants—machine, engine, and dynamo oils; and 42 miscellaneous

materials, adhesives, etc., in all, 3,580 tests of materials, as compared

with 1,716 in the preceding year. The increase in testing has been

general in all branches of the work, the most marked increase being

in textiles and papers.

Recent additions to the equipment will enable the Bureau to

undertake some valuable investigations. Among the new apparatus

acquired for metal investigations are a Keep hardness tester, a Ballentine hardness tester, a Brinell hardness tester, a Shore scleroscope, a cold-bending machine (motor driven), and a Souther alternating

stress machine. A high-grade microscope, with a mechanical state,

has been added to the equipment for fiber work. A Riehle cement

tester and a 12-spool yarn reel have been delivered, and orders are outstanding for a Turner-Landgraf alternating-impact machine, a cement permeability apparatus, a 1,000,000-pound special RiehlS

crushing machine, a 230,000-pound improved Emery testing machine, 150-meter kilogram torsion machine, a Danto Roguet conditioning apparatus, a Corte yarn reel, and Corte conditioning oven.

LIBRARY.

An mportant part of the equipment of the Bureau is the library,

which now contains 4,941 technical and scientific works, mainly in

physics, chemistry, mathematics, and engineering. During the year

380 volumes were added to the library and 180 periodical publications

were regularly received.

The library is catalogued upon the classification used at the Library

of Congress, the printed cards issued by that library being used as far as available. The facilities of the scientific libraries in Washington

are also available for reference. Access to the complete literature in

any technical subject is essential to the best work, especially in new

investigations.
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 21

PUBLICATIONS.

During the year 23 technical papers relating to standards and precision measurements were published, giving the results of researches

and investigations conducted by the Bureau of Standards. Six

bureau circulars were published giving information as to methods of

testing specifications for standards and measuring instruments and

regulations in regard to their verification, i. e., Circular 13, "Standard

specifications for the purchase of incandescent electric lamps"

(revised to include the new high-efficiency filament lamps) ; Circular

14, "Analyzed irons and steels—Methods of analysis;" Circular 15,

"A proposed international unit of light;" Circular 16, "The testing

of hydrometers;" Circular 17, "Magnetic testing;" and Circular 18,

"United States standard sheet-metal gauge." A new edition of the

chart of the international metric system was also issued.

BUILDINGS AND GROUNDS.

The contract for the new laboratory building authorized by Congress was awarded early in the year, and the construction is nearly

completed. Plans are now being drawn for the installation of the

apparatus and machinery. The new laboratory harmonizes in style,

appearance, and location with the other buildings, and has been

designed in details to meet the needs of the work.

The new laboratory has four stories and is of fireproof construction,

of brick trimmed with limestone. The first floor is especially suitable

for heavy testing apparatus and for work requiring great stability.

The large testing machine will be installed in the new building. It is expected that the laboratory will be ready for use early in 1910.

The grading has been continued along the lines previously laid out,

but additional roadway and walks will be needed for the new building.

SUMMARY OF TESTS.

The work of the Bureau involves, among other things, a large

amount of testing of standards, measuring instruments, and materials. A certain amount of this work is already organized upon an

accurate routine basis. Much of it, however, involves investigation

of the scientific principles underlying the test, a study of existing

methods, and the development of new standard tests of known accuracy. In such cases the research which must precede the actual testing is a most important function of the Bureau. For the test a rea- sonable fee is charged, except when made for the National or State

Governments. The corresponding amounts for government testing are of interest, however, and are added to the statement of tests which

follows
22 REPORT OP DIRECTOR OE BUREAU OF STANDARDS.

Number and Value op Tests Completed, Fiscal Year ended June 30, 1909.

liatuic yji Lest.

For Government. For public. Total.

Number. Value. Number. Value. Number. Value.

Length 460 $1,091.10 106 $257. 80 566 $1, 348. 90 Mass 1,635 700. 55 463 290. 95 2,098 991.50 Capacity 10, 386 3, 196. 15 379 322. 90 10, 765 3,519.05 3,812 1,521.25 9,129 1, 926. 37 12,941 3, 447. 62 Optical 1,287 1, 304. 00 29 58.00 1,316 1,362.00 Engineering 2,082 7, 190. 10 122 269. 63 2,204 7,459. 73

Electrical 151 531. 70 314 1, 159. 70 465 1,691.40 Photometry 2,668 5,226.20 1,256 336. 50 3,924 5,562.70 Chemical 1,972 7, 681. 26 549 925. 60 2,521 8, 606. 86 Miscellaneous 1, 176 900. 75 113 101. 60 1,289 1,002.35

Total 25, 629 29, 343. 06 12, 460 5, 649. 05 38, 089 34,992.11

Besides , the foregoing the Bureau inspected 628,400 incandescent

lamps at various factories for other departments of the Government,

the fees for which would amount to $3,142 additional, making the

total value of work done for the Government $32,485.06.

The number of tests made for the Government in the fiscal year

1909, exclusive of lamps inspected at factory, was 159 per cent

greater than in the preceding year, and the number of tests for the

public was 15 per cent greater, the increase in tests for both Government and public amounting to 84 per cent.

The receipts for tests were as follows:

Total receipts, 1909 - $6, 001. 06

Received prior to July 1, 1908, for tests completed in fiscal year 1909. $90. 98

Outstanding fees 124. 40

Canceled test and refunds 16. 92

232. 30

6, 233. 36

Received for tests in progress at close of fiscal year 1908-9 584. 31

Fees for tests completed, 1908-9 5: 649. 05

FINANCIAL STATEMENT.

The following statement shows the amount and object of each

appropriation provided for the Bureau for the fiscal year 1909, the

disbursement during the year, the amount of unfilled and unpaid

orders at the close of the year, and the unexpended balance remaining

at the close of business June 30, 1909:

Appropriation. Appropriated. Disbursed. Liability. Balance.

$141,540. 00

41,000. 00

15, 000. 00

3,000. 00

$138, 765. 11 30,131.53

12,737.49

2, 997. 22

$2,774.89

183. 55

1,040. 86 2.78

$10, 684. 92 General expenses 1,221.65

Total 200, 540. 00 184,631.35 11, 906. 57 4, 002. 08
REPORT OF DIRECTOR OF BUREAU OF STANDARDS. 23

The following statement shows the condition of the appropriations

for the two fiscal years preceding 1909 at the close of business June

30, 1909:

Appropriation.

1907. 1908.

Appropriated. Disbursed. Liability. Balance. Appropriated. Disbursed. Liability. Balance.

Salaries $111,440.00 41.000.00

15.027.50 3.000.00

$108,399.59-

40,502.49

15, 023. 48 3,000.00

$429.'73'

S3. 040. 41 67.78 4.02

$130,620.00 41.000.00

15,000.00 3,000.00

1

$123, 874. 24

40,051. 21

14,883. 97 2,982.86

S6, 745. 76 341.66 96.77

17.14

Equipment

General expenses. Grounds

$607. 13 19.26

Total 170,467.50 166,925.56 429.73 3, 112. 21 189,620.00 181,792.28 626.39 7,201.33

Respectfully,

S. W. Stratton, Director.

To Hon. Charles Nagel,

Secretary of Commerce and Labor.

o